“Over the past several decades, treatment of cancer in adolescents and young adults (AYAs) has evolved substantially, leading to steady improvements in estimated five-year survival at diagnosis. However, the impact on late mortality in this population is largely unexamined,” the researchers established.

The study authors queried the Surveillance, Epidemiology, and End Results database for data on patients aged between 15 and 39 years who received a cancer diagnosis between 1975 and 2011 and survived for at least five years after their diagnosis; months of survival from five years post-diagnosis until death or the end of 2016 were accrued.

Late Mortality Rates Declining, But Not Only Due to Primary Cancer

Final analysis included 282,969 five-year adolescent and young adult cancer survivors. Five-year mortality in patients diagnosed between 1975 and 1984 was 8.3% (95% confidence interval [CI], 8.0% to 8.6%); this decreased to 5.4% (95% CI, 5.3% to 5.6%) for patients diagnosed between 2005 and 2011. The primary driver was decreases in mortality from the primary cancer, which decreased from 6.8% to 4.2% during the respective time periods, but this was not the case for some specific cancers—including colorectal, bone, sarcomas, cervical/uterine, and bladder—for which cumulative mortality curves presented only little improvement over the study period. In Hodgkin lymphoma, leukemia, kidney cancer, head and neck cancers, and trachea, lung, and bronchus cancers, late mortality due to noncancer/nonexternal causes was reduced.

“It is important that we monitor trends in survival not only among recently diagnosed patients, but also among survivors who are several years beyond their initial cancer diagnosis,” said lead study author Chelsea Anderson, PhD, in a press release. “There have been substantial improvements over the past several decades for five-year survivors, though some cancer types have not shared in these improvements. Survivors of these cancer types may therefore be priority groups for efforts to improve long-term surveillance to reduce late mortality from cancer among adolescents and young adults.”